public class Test {
    public static void main(String[] args) {
        Thread t1 = new Thread(() -> {

                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            System.out.println("这是c线程");
        });

        Thread t2 = new Thread(() -> {

                try {
                    Thread.sleep(2000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            System.out.println("这是b线程");

        });

        Thread t3 = new Thread(() -> {
                try {
                    Thread.sleep(3000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            System.out.println("这是a线程");

        });
        t1.start();
        t2.start();
        t3.start();
        System.out.println("线程开始");
    }
}